(1) Field of the Invention
The present invention relates to beryllium-copper alloys which have high electrical conductivity and high strength and which are used as connectors, relays, etc. More particularly, the invention relates to a process for producing beryllium-copper alloys which possess excellent strength and formability due to the presence of finely dispersed solid-unsolved precipitate.
(2) Related Art Statement
A variety of beryllium-copper alloys have formerly widely been used as wrought materials for electronic parts, etc. making the most of their characteristics of high electrical conductivity and high strength. In the production of these beryllium-copper alloys, as shown in a flow chart of FIG. 3, a cast ingot consisting of Cu, Be and other auxiliary component or components is obtained, is subjected to a solution treatment, for instance, at 750.degree. to 950.degree. C., is cold worked, and then is age hardened, thereby obtaining a desired beryllium-copper alloy.
However, in the conventional production of the alloys mentioned above, the solution treatment is performed to improve strength and formability with a solid-unsolved intermetallic compound formed between Be and an auxiliary additive component or components. However, a great amount of coarse solid-unsolved precipitate of, for example, not less than 0.3 .mu.m are recognized in the beryllium-copper alloys having undergone the above solution treatment. Thus, there is a problem that strength or formability cannot fully be improved.
By the way, strength can be increased in this case by solid-solving a part of the solid-unsolved precipitates through merely raising a solution treating temperature. However, since the grain size in a matrix simultaneously becomes greater, this technique has a defect that a great problem occurs in formability.